1. Field of Invention
The present invention is related to systems and methods for determining a surface profile of a droplet on a complex surface.
2. Description of Related Art
Applying inkjet technology to the industrial printing process can greatly improve its efficiency. Inkjet technology can be used to save energy, material, money, and it can also help improve the environment. Inkjet technology may be used in the manufacture of liquid crystal displays (LCD), thin film transistors (TFT), organic light emitting diodes (OLED), solar cells, micro-circuits, and other planar, layered, or 3-D structures. In the inkjet printing process, small droplets of a solution are deposited onto a target area.
Once the droplet is deposited onto a substrate it takes on an initial equilibrium droplet shape. The droplet shape is defined by a droplet interface. The droplet interface represents the extant of the droplet within an environment. The droplet interface is very dependent upon the contact angle of the droplet and the droplet volume. The contact angle is an angle at which the droplet interface intersects the substrate. The contact angle is dependent upon the interaction of the droplet, the substrate, and the environment. Although not trivial, simulation tools do exist that provide reasonably accurate estimates of the droplet interface when the substrate is flat.
One method of estimating a droplet interface is to use a minimization routine such as the one found in Surface Evolver that starts with an initial guess of the shape of the droplet interface and then minimizes an energy function to come up with a better estimate of the droplet interface. This method can work well, if the initial guess is good, the substrate is flat, and the energy function is accurate. Obtaining an optimum droplet interface when the substrate is not flat can be very difficult and is very dependent upon the initial guess. For example, if the substrate includes a curved bank structure such as those found in OLED production can be very difficult.
The present invention is directed towards systems and methods for making an initial estimate of the shape of a droplet given the shape of the substrate, the volume of the droplet, and the contact angle.